Tram control system



Feb. 24, 1970 F. E. OSLAKOVIC ET AL 3,497,055

TRAM CONTROL SYSTEM Filed Aug. 28, 1967 5 Sheets-Sheet l g; H E] II Feb. 24, 1970 F. E. OSLAKOVIC ET AL 3,497,055

TRAM CONTROL SYSTEM .5 Sheets-Sheet 2 Filed Aug. 28, 1967 Feb. 24, 1970 F. E. OSLAKOVIC ET AL 3,497,055

TRAM CONTROL SYSTEM Filed Aug. 28, 1967 5 Sheets-Sheet 5 710 f far/er .5 Sheets-Sheet 4 TRAM CONTROL SYSTEM F. E. OSLAKOVIC ET AL Feb. 24, 1970 Filed Aug. 28, 1967 &

.5 Sheets-Sheet 5 F. E. OSLAKOVIC E AL TRAM CONTROL SYSTEM Feb. 24, 1970 Filed Aug. 28, 1967 United States Patent Ofifice 3,497,055 Patented Feb. 24, 1970 3,497,055 TRAM CONTROL SYSTEM Frank E. Oslakovic, Chicago, and Donald C. Reilly, Downers Grove, Ill., assignors to Westinghouse Air Brake Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 28, 1967, Ser. No. 664,236 Int. Cl. B65g 37/00, 47/31 U.S. Cl. 198-92 15 Claims ABSTRACT OF THE DISCLOSURE A train system having a self-propelled unit at each end coupled to intermediate units, each end unit being capable of towing the intermediate units, but not the Other end unit, irrespective of the direction of movement. An electro-hydraulic system ensures that the lead unit reaches high speed first, and thereafter slows down and then speeds up if the lead unit advances relative to the trailing unit. The system also ensures that the trailing unit slow down and then speed up if it advances relative to the lead unit. By suitable regulation of the switches in the electro-hydraulic circuit a predetermined draw bar tension between the units is not exceeded so that the lead unit never tows the trailing unit, and the trailing unit never pushes the intermediate unit.

This invention relates to a method and system for controlling the tramming movement of a multi-unit train consisting of at least two end units, one of which leads and the other of which trails, and an intermediate unit. It is specifically directed to causing the vanguard or lead unit to tow the intermediate unit irrespective of the direction of movement of the train. The invention is further concerned with means for causing the lead unit to move at different rates of speed and the trailing unit to move at a suitably reflected rate of speed.

Accordingly, a primary object of the invention is to provide a method of causing the lead unit in a multi-unit train to tow the intermediate unit or units, but not the trailing unit, irrespective of the direction of movement of the train.

Another object is to provide a method of maintaining the drawbar tension between the units of a multi-unit train within predetermined limits.

Yet another object is to provide apparatus for accomplishing the above objects.

Other objects and advantages of the invention will become apparent from reading the following description:

The invention is illustrated more or less diagrammatically in the accompanying figures wherein:

FIGURE 1 is a partly diagrammatic top plan view of a multi-unit train embodying the invention;

FIGURE 2 is a side elevation of the multi-unit train of FIGURE 1;

FIGURE 3 is a side view, to an enlarged scale, of the coupling mechanism between adjacent units;

FIGURE 4 is a top view of the coupling mechanism of FIGURE 3;

FIGURE 5 is a view taken substantially along the line 55 of FIGURE 4;

FIGURE 6 is a sectional view of the spring mechanism associated with each coupling means;

FIGURE 7 is a top plan view of the cam box with the cover removed;

FIGURE 8 is an end view of the cam box of FIG- URE 7 with a portion of one end removed;

FIGURE 9 is a schematic diagram of the electromechanical system for controlling the tramming movement of the inby and outby units showing the units in a condition of maximum speed; and

FIGURE 10 is a schematic diagram of the system of FIGURE 9 in a condition in which the inby unit is moving at low speed and the outby unit is moving at high speed.

Like reference numerals will be used to refer to like parts from figure to figure.

Although it is contemplated that the invention may, with appropriate modification, be applied to any multitram system in which the leading one of two end units is required to tow the intermediate unit, the invention will be described as applied to a coal mining system. In the illustrated system an inby tram unit is connected by coupling means to an intermediate unit or units which in turn are coupled to an outby unit. The inby unit is positioned to receive coal from a borer and convey the mined coal, usually by means of a belt conveyor, to a trailing intermediate conveyor unit. Each conveyor unit discharges onto a trailing conveyor unit, the last conveyor unit discharging onto the outby unit which in turn discharges the coal into a storage pile or removal system.

For further description of a typical mining system to which the invention may be applied reference is made to copending applications Ser. Nos. 655,413 and 655,426, assigned to the assignee of this application.

An inby conveyor unit is indicated generally at 10 in FIGURES l and 2. The inby unit discharges coal onto an intermediate conveying unit 11 which in turn discharges onto any suitable number of similar trailing units, the last of which is indicated at 12. Conveyor unit 12 discharges onto outby unit 13 which is equipped with a short conveyor 14 for discharge onto a truck or other removal means, and a long conveyor 15 for discharge into a storage pile.

The source of power, which may for example be a hydraulic motor, is indicated at M1 on inby unit 10 and a similar source of power is indicated at M2 on outby unit 13. It will be understood that when the train moves to the right, as viewed in FIGURES 1 and 2, it is necessary for the inby unit 10 to tow the intermediate units 11, 12 which, for purposes of illustration, will be assumed to have no self-contained power system, and outby unit 13 must be self-propelling. When the train moves in the reverse direction, that is to the left as viewed in FIG- URES 1 and 2, outby unit 13 which then becomes the lead unit is required to tow the intermediate units 11 and 12, and inby unit 111, which then becomes the trailing unit, must be self-propelled.

A typical coupling mechanism for coupling one unit to an adjacent unit is indicated in FIGURES 3-6.

The frame of inby unit 10 is indicated at 20, 21 and 22. Means for providing relative movement between adjacent units, in this instance a pair of spring assemblies are indicated at 23 and 24, the housings of the spring assemblies being connected to cross frame member 22 by a plate 25 and bolts 26. Reinforcing struts are indicated at 27.

Housing assembly 23 includes end plates 28, 29. An aperture 30 in end plate 29 receives a connecting rod 31 which terminates, at one end, in a flange 32 and at the other end in an aperture 33. A relatively light spring is indicated at 34- and a heavier spring at 35. Connecting rod 31 has an axial bore 36 which receives a guidepin 37. A relatively light spring is indicated at 38.

The left end of connecting rod 31 is connected by a pin 40 to a universal connector indicated generally at 41. The universal connector is in turn connected to a drawbar 42 which is integral with the conveyor unit 11.

A cam box is indicated at 45. The cam box includes a horizontally extending projection or sleeve 46 which accommodates a cam rod 47. The left end of rod 47 is connected by suitable linkage 48 and a motion permitting connector 49 to the connection rods 31.

Cam rod 47 includes a first portion having a small diameter 50, and a second portion having a larger diameter 51, the two portions being separated by shoulder 52. Four switches are indicated at 1, 2, 3 and 4. As best shown in FIGURE 8, the switches are oriented at 90 degrees with respect to one another but it will be understood that within the scope of the invention they could all be in line.

Referring now to FIGURES 9 and 10, it will be noted that hydraulic motor M1, which powers inby unit 10, is incorporated in a hydraulic circuit which includes a pump B, a relief valve 5, a direction control valve C and a solenoid operated flow control valve A.

Valve C, which is also solenoid operated and includes a forward direction coil CF and a reverse direction coil CR, is a three-position valve. When neither the forward coil CF or reverse coil CR is energized the valve is in neutral, and flow is circulated back to tank. If forward coil is energized, the output from pump B passes into line B. If flow control valve A is in the illustrated blocking position the entire pump output goes through M1 and inby unit 10 moves in a forward direction at high speed. If the reverse coil CR is energized, the output from pump B passes into line G. If flow control valve A is in the blocking position the entire pump output goes through M1 in the direction of the dotted arrow beneath it, and inby unit 10 moves in a reverse direction at high speed as will be described in detail hereinafter.

If flow control valve A is in a non-blocking position and forward coil CF is energized, a portion of the pump output is diverted through lines H and I back to tank, and inby tram unit 10 is propelled at a lower speed. The speed of inby tram unit 10 is directly proportional to the volume flow through the motor M1.

It will thus be seen that the key to high speed or low speed movement of inby unit 10 is whether flow control valve A is energized or de-energized.

It should be understood that for purposes of convenience only a single pump and a single flow control valve have been illustrated. A greater or lesser number may be used, as desired.

Referring now to the electrical portion of the diagram, a run button is indicated at Ll. When L1 is depressed contacts A2 and L3 are also closed.

Closure of contact L1 completes a circuit composed of lines M, N, relay coil Q, switches 3 and 4, and lines R, S, T and U.

Energization of coil Q closes relays V1 and V2. Closure of V2 completes a circuit through the coil of flow control valve A comprising lines M, P, coil A, lines R, S, T and U which thereby blocks fluid flow therepast and directs the entire pump output through the motor M1. As a result inby unit 10 moves forward at high speed.

It should be understood that the instant before contact L1 was depressed, switches 1, 3 and 4 were closed and switch 2 was open. This condition is shown in FIG- URES 7 and 8.

As inby unit 10 trams forward cam box 45, which is bolted to unit 10, pulls switches 1 and 2 to the right with respect to rod 47 which remains stationary for the time being. The initial increment of movement causes switch 2 to close. Switch 2 is a make-ready switch which, when closed, energizes a circuit which includes lines U, T, S, R, switch 2, line Z, switch 1-0, line W, the coil of TD-O, and lines X and M.

It will be noted that the hydraulic and electrical circuits for the inby and outby tram units are substant ally identical. Accordingly, components in the outby tram unit circuits which correspond to a similar component in the inby tram unit circuits will be identified by the same letter or number and the sufiix -0.

Energization of the time delay coil TD causes contact TD1-0 to close after a suitable time period, such as a second. Closure of switch T1314) completes the circuit which includes coil Q-0, switches 3-0 and 4-0, and line M. However, due to transient conditions this last mentioned circuit is not relied on to maintain Q-0 energized. Rather, a circuit comprising switch TD10 line Y, coil Q-0, and line V, switch L2 and line M is maintained. Energization of coil Q-0 causes contacts V1-0 and V2-0 to close, thereby energizing flow control valve A-O by completion of a circuit which includes line M, coil A-0, switch V20, and lines T and U. As a result motor M2 will cause outby tram unit 13 to move forward at a high rate of speed since it will be noted that when the coil of A-0 is energized and the valve is placed in a blocking condition, the entire output of pump B-O will pass through M2 in the direction of the solid arrow and outby tram unit 13 will move in a forward direction at high speed.

It should be noted that contact L3 is a direction control switch. That is, when the tram button L1 is depressed switch L3 closes to establish a circuit through line M, switch L3, line .100, coils CF and CF-0, and lines S, T and U. As a consequence both the inby and outby tram units will move in a forward direction since the energization of the F coil in each of valves C and C-0 causes hydraulic fluid in each hydraulic circuit to drive its respective motor in a direction which results in forward movement of both the inby and outby tram. Although both tram units started to move in a forward direction at the same instant because valves C and C-0 were simultaneously actuated, it should be remembered that outby tram unit 13 reached high speed condition last because of the delay derived from time delay switch TDl-(l.

It should further be noted that depression of tram button L1 effectively bypassed or knocked out coil TD. This is necessary because no time delay should occur in the inby tram unit circuit when the inby tram unit is started in a forward direction.

It will also be noted that closure of contact L2 effectively cuts out switches 40 and 30 for a purpose which will be explained hereinafter.

Now assume that the inby tram unit is moving in a forward direction faster than desired, that is, faster than the movement of the outby tram unit 13 Since cam box 45 is carried by inby tram unit 10, relative displacement of the cam box 45 to the. right with respect to rod 47 first causes switch 3 to open. No immediate change in speed takes place, however, because a circuit is maintained through coil Q which controls switch V-2 and thereby flow control valve A, by a bypass circuit which includes coil Q, line 101, switch V1, line 102, switch 4, and lines R, S, T and U.

As inby tram unit 10 continues to draw away from the first conveyor unit 11 switch 4 opens. This condition is illustrated in FIGURE 10. Opening of switch 4 deenergizes coil Q which opens switch V-2. As a result the coil of flow control valve A is deenergized.

When flow control valve A is deenergized a portion of the output from the pump passes through the valve as illustrated in FIGURE 10, and accordingly the quantity of fluid passing through motor M1 is decreased. The Speed of inby tram unit 10 therefore drops. In this condition the springs 35 in the coupling assemblies, which had been compressed as the inby tram unit 10 pulled away from the trailing conveyor units, relax and conveyor unit 11 begins to catch up with inby tram unit 10. In this connection it is important to note that the outby tram unit 13 does not push the units together. The closing movement occurs due to relaxation of springs 34 and 35.

As conveyor unit 11 catches up with inby tram unit 10, switch 4 is closed, but no immediate change in the speed occurs. Thereafter switch 3 closes which reestablishes the circuit comprised of line M, switch L1, coil Q, switches 3 and 4, and lines R, S, T and U. As noted above, energization of coil Q closes switch V2 which completes the earlier described circuit to the solenoid of flow control valve A. The coil Q holding circuit which includes line 101 is also reestablished. Energization of the solenoid moves the valve to a flow blocking position and high speed of inby tram unit is reestablished.

Now assume that the outby tram unit 13 has been moving too fast; that is, it is creeping up on inby tram unit 10. When this occurs switch 1-0 will open because rod 47-0 will move to the right at a faster speed than will switch 10. Opening of switch 10 breaks the circuit through coil TD-0 and contact TD0 opens. Opening this contact breaks the circuit through coil Q-0- and accordingly switch V20 is opened. This breaks the circuit through the solenoid of flow control valve A-0 and consequently a portion of the hydraulic fluid is bypassed to tank and the speed of motor M2, and consequently outby tram 13, is slowed.

Now assume outby tram unit 13 is moving too slow relative to inby tram unit 10. Switch 10 closes. A circuit is thereby reestablished through TD-0 which closes switch TD1-0 thereby energizing coil Q-0. Flow control valve A-0 is thereby energized, blockage of the hydraulic fluid in line H-O is restored, and motor M2 is caused to operate at high speed.

Now assume the system is stopped and is to be started in a reverse direction, that is to the left as viewed in FIG- URES 1 and 2.

Refer to FIGURE 10. Outby unit tram button L1-0 is depressed, and consequently contacts L20 and L3-0 are closed. Closure of L3-0 establishes a circuit which includes M, 103, CR-O, CR, 104, L3-0, T and U. Direction control valves C-0 and C are now in the proper position.

As switch L10 closes, a circuit is established which includes line M, switches 4-0 and 3-0, coil Q-0, switch L1-0, and lines T and U. Energization of coil Q-0 closes switches V10 and V20 thereby completing a circuit through the coil of flow control valve A-t) Which comprises M, A-O, V24), T and U. Flow control valve A-0 is thus placed in a blocking position and the entire pump output flows throungh motor M2, thereby causing outby tram unit 13 to move at a high speed in a reverse direction. Inby tram unit 10 will likewise move in a reverse direction, but at a lower speed because flow control valve A is in the partial flow condition illustrated in FIGURE 10 temporarily. As soon as the time delay derived from coil TD expires, flow control valve A will be placed in a fully blocked condition, as earlier described, and the inby unit will move in the reverse direction at high speed.

It will be understood that very shortly after outby tram unit 13 began to move in a reverse direction, switch 2-0 closed.

It will be understood that when the above described conditions of relative displacement between the inby and outby tram units occur as was discussed in connection with movement in a forward direction, the same operations will take place with the same results. In view of the identity of the circuitry a detailed description of the functioning of the circuits associated with each condition is not necessary to one skilled in the art.

Although a preferred embodiment of the invention has been illustrated and described it will be at once apparent to those skilled in the art that modifications may be made within the scope of the invention. Accordingly, it is intended that the scope of the invention be not limited by the foregoing illustrative description, but solely by the scope of the hereinafter appended claims when construed in light of the pertinent prior art.

What is claimed is:

1. In combination in a multi-unit train,

a first end unit,

a second end unit,

an intermediate unit or units disposed between the end units,

mechanical coupling means between each end unit and its adjacent unit, and

means for automatically coupling the intermediate unit to the lead end unit irrespective of the direction of movement of the train,

said automatic coupling means including an electrohydraulic system having means for starting the first end unit, and thereby the intermediate unit, in a forward direction of movement in response to a starting signal at an initial speed, and

means for causing the second end unit to reach the initial speed of the first unit at a time subsequent to starting of the first end unit and the intermediate unit, and thereafter maintaining said second, trailing end unit at substantially the same initial speed.

2. The combination of claim 1 further characterized in that the mechanical coupling means includes means which permit relative movement between the end units and the intermediate unit,

said relative motion means having a limit of movement sufficient to enable either end unit to move in either direction a distance suflicient to set the towed intermediate unit in motion prior to imposition of a direct towing force on the trailing unit by the lead unit.

3. The combination of claim 2 further including means for slowing the first end unit, in the event it advances too far relative to the second end unit, until the second end unit closes to a pre-determined position, and

means for thereafter reestablishing the initial speed of the first end unit.

4. The combination of claim 2 further including means for slowing the second end unit in the event it advances too far relative to the first end unit, until the first end unit advances to a pre-determined position relative to the second end unit, and

means for thereafter reestablishing the initial speed of the second end unit.

5. The combination of claim 2 further characterized in that the automatic coupling means and electro-hydraulic system includes first hydraulic motor means associated With the first end unit,

second hydraulic motor means associated with the second end unit,

a first electrical circuit associated with the first hydraulic motor means for enabling the first hydraulic motor means to be drivingly connected to the first end unit,

a second electrical circuit associated with the second hydraulic motor means for enabling the second hydraulic motor means to be drivingly connected to the second end unit,

said second electrical circuit means having time delay means associated therewith which is effective to delay operation of the second hydraulic motor means at the same initial speed as the first hydraulic motor means for a pre-determined delay period after connection of the first hydraulic motor means to the first end unit under that condition in which the first end unit is the lead unit.

6. The combination of claim 5 further characterized in that the first electrical circuit means has time delay means associated therewith which is effective to delay operation of the first hydraulic motor means at the same initial speed as the second hydraulic motor means for a pre-determined delay period after connection of the second hydraulic motor means to the second end unit under that condition in which the second end unit is the lead unit.

7. The combination of claim 2 further characterized in that the first end unit is a self-propelled conveyor unit adapted to receive cuttings,

the intermediate unit is a conveyor unit adapted to convey cuttings which have been received by the first end unit, and

the second end unit is a self-propelled discharge unit adapted to discharge cuttings conveyed to it by the intermediate unit. 8. The combination of claim 1 further characterized in that,

firstly, the mechanical coupling means between each unit includes relative motion means which are connected to and movable relative to plunger means,

said relative motion means being operatively connected to one unit and the plunger means to the other unit, and

secondly, in that the electro-hydraulic system includes cam means operatively associated with one unit and cam follower means operatively associated with the other units,

said cam means and cam follower means actuating switches in electrical circuits which control slow down and speed up conditions of the end units,

said cam means and cam follower means being constructed and arranged to move relative to one another proportionately to movement between the units as reflected by the relative motion means.

9. A multi-unit train having two end units connected for movement in the same direction, power tram means for each end unit, and control means for said power tram means effective to energize each of said power tram means independently to move both of said end units independently in the same direction without transmission of substantial tractive forces from either of said end units to the other, said control means including means sensing relative motion between the end units to energize either of the associated power tram means to maintain their relative positions.

10. A multi-unit train according to claim 9 in which an intermediate unit is connected between the end units, and the intermediate unit is moved by tractive force transmitted from a single one of said end units.

11. In combination with a multi-unit train having two end units and an intermediate unit,

means for automatically coupling the intermediate but not the trailing, unit to the lead end unit irrespective of the direction of movement of the train,

means for automatically slowing whichever one of the two end units is moving too fast relative to the other end unit irrespective of the direction of travel of the train, and

relative motion means connecting each end unit to its adjacent unit whereby the tension between adjacent units may vary between limits defined by the relative motion means and switch means associated with the automatic coupling means.

12. A multi-unit train having leading and trailing end units connected for movement in the same direction,

power tram means for both of said units,

control means for the trailing end unit tram means effective to energize the trailing end unit tram means to move the trailing end unit in response to leading movement of said leading end unit,

said end units being connected by means including conpling means enabling limited relative movement between the end units, and said control means is operable responsive to said relative movement for energizing the trailing end unit tram means to maintain the trailing end unit in a predetermined position with respect to the leading end unit while the latter is moving in a leading direction.

13. A multi-unit train having leading and trailing end units connected for movement in the same direction,

power tram means for both of said units,

control means for the trailing end unit tram means effective to energize the trailing end unit tram means to move the trailing end unit in response to leading movement of said leading end unit,

an intermediate unit connected between the end units,

and

coupling means disposed between the trailing end unit and the intermediate unit, said coupling means enabling relative longitudinal movement between the trailing end unit and the intermediate unit, and said,

control means is operable responsive to said relative movement for energizing the trailing end unit tram means to maintain a predetermined position with respect to the intermediate unit while the latter is moving with the leading unit in a leading direction.

14. A multi-unit train according to claim 13 in which both leading and trailing end units are provided with power tram means, and said control means is operable responsive to relative movement at either of said coupling means for energizing either of said power tram means.

15. A multi-unit train having leading and trailing end units connected for movement in the same direction,

power tram means for both of said units,

control means for the trailing end unit tram means effcctive to energize the trailing end unit tram means to move the trailing end unit in response to leading movement of said leading end unit,

an intermediate unit connected between the end units,

and

coupling means disposed respectively between each end unit and said intermediate unit, each coupling means enabling relative longitudinal movement between the intermediate unit and a corresponding one of said end units, and said control means is operable responsive to relative movement at one of said coupling means for energizing the trailing end unit tram means to maintain the trailing end unit in a predetermined position with respect to the leading end unit while the intermediate unit is moving with the leading end unit in a leading direction.

References Cited UNITED STATES PATENTS RICHARD E. AEGERTER, Primary Examiner Us. 01. X.R. 1so-14 

